Imaging of pediatric brain tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee/ASPNR White Paper

Tumors of the central nervous system are the most common solid malignancies in children and the most common cause of pediatric cancer-related mortality. Imaging plays a central role in diagnosis, staging, treatment planning, and response assessment of pediatric brain tumors. However, the substantial variability in brain tumor imaging protocols across institutions leads to variability in patient risk stratification and treatment decisions, and complicates comparisons of clinical trial results. This White Paper provides consensus-based imaging recommendations for evaluating pediatric patients with primary brain tumors. The proposed brain magnetic resonance imaging protocol recommendations balance advancements in imaging techniques with the practicality of deployment across most imaging centers.

Dots and spots: A retrospective review of T2-hyperintense white matter lesions in pediatric patients with and without headache

OBJECTIVE

We aimed to determine if T2-weighted hyperintense white matter lesions (WMLs) on brain magnetic resonance imaging (MRI) occur more frequently in pediatric patients with migraine and other primary headache disorders compared to the general pediatric population.

BACKGROUND

Small foci of T2 hyperintensity in the white matter are frequently identified on brain MRI during the workup of pediatric headache. Such lesions have been reported to be more common among adults with migraine versus adults without migraine; however, this association has not been well established in the pediatric population.

METHODS

We performed a retrospective cross-sectional single-center study of electronic medical records and radiologic studies, examining pediatric patients from 3 to 18 years old who underwent brain MRI between 2016 and 2021. Patients with existing intracranial disease or abnormalities were excluded. Patients with reports of headache were categorized. Imaging was reviewed to determine the number and location of WMLs. Headache-associated disability scores (Pediatric Migraine Disability Assessment) were noted, when available.

RESULTS

Brain MRI of 248 patients with a diagnosis of headache (144 with migraine, 42 with non-migraine primary headache, and 62 with headache that could not be further classified) and 490 controls were reviewed. WMLs were encountered commonly among all study participants, with a prevalence of 40.5% (17/42) to 54.1% (265/490). There was no statistically significant difference comparing the number of lesions between each of the headache groups and the control group: migraine group versus control group median [interquartile range (IQR)], 0 [0-3] versus 1 [0-4], incidence rate ratio [95% confidence interval (CI)], 0.99 [0.69-1.44], p = 0.989, non-migraine headache group versus control group median [IQR], 0 [0-3] versus 1 [0-4], 0.71 [0.46-1.31], p = 0.156, headache not otherwise specified group versus control group median [IQR], 0 [0-4] versus 1 [0-4], 0.77 [0.45-1.31], p = 0.291. There was no significant correlation between headache-associated disability and the number of WMLs (0.07 [-0.30 to 0.17], rho [95% CI]).

CONCLUSION

T2 hyperintense WMLs are common within the pediatric population and are not encountered more frequently in pediatric patients with migraine or other primary headache disorders. Thus, such lesions are presumably incidental and unlikely related to headache history.

Refining the role of cervical spine immobilization and stabilization in pediatric non-accidental trauma, a retrospective series of 1008 patients

INTRODUCTION

Prompt detection of traumatic cervical spine injury is important as delayed or missed diagnosis can have disastrous consequences. Given the understood mechanism of non-accidental trauma (NAT), it is reasonable to suspect that cervical spine injury can occur. Current management of young children being evaluated for NAT includes placement of a rigid collar until clinical clearance or an MRI can be obtained. Currently, there exists a lack of robust data to guide cervical bracing. Anecdotally, our group has not observed a single patient with a diagnosis of NAT who required operative stabilization for cervical spine instability. This study will be the largest series to date and aims to systematically investigate this observation to determine the likelihood that children with a diagnosis of NAT harbor cervical spine instability related to their injuries.

METHODS

Patient data from the Children's Hospital Colorado Trauma Registry diagnosed with non-burn-only NAT were reviewed retrospectively. Children less than 4 years of age pulled from the registry from January 1, 2005, to March 31, 2021, were included. Demographic, admission/discharge, imaging, and clinic management data were collected for each patient and analyzed.

RESULTS

There were 1008 patients included in the cohort. The age at presentation ranged from 5 days to 4 years (mean 10.4 months). No patient had X-ray or CT findings concerning for cervical instability. Three patients had MRI findings concerning for cervical instability. Two of these underwent external bracing, and the third died from unrelated injuries during their hospitalization. Only four patients were discharged in a cervical collar, and all were ultimately cleared from bracing. No patient underwent a spinal stabilization procedure.

CONCLUSIONS

While the mechanism of injury in many NAT cases would seem to make significant cervical spine injury possible, this single-center retrospective review of a large experience indicates that such injury is exceedingly rare. Further study is merited to understand the underlying pathophysiology. However, it is reasonable to consider cervical collar clearance in the setting of normal radiographs and a reassuring neurological exam. Furthermore, if concerns exist regarding cervical spine instability on MRI, an initial trial of conservative management is warranted.

Thalamic Volume Loss Is Greater in Children Than in Adults Following Middle Cerebral Artery Territory Arterial Ischemic Stroke

Background: Younger stroke patients may suffer worse outcomes than older patients; however, the extent to which age at stroke impacts remote areas of the brain remains unclear. The objective of this study was to determine thalamic volume changes ipsilateral to middle cerebral artery territory strokes based on age at acute ischemic stroke onset. Methods: Acute ischemic stroke patients <9 years, 9-18 years, and >18 years old were retrospectively recruited from a large quaternary care system. Each subject underwent an acute (<72 hours from AIS) and chronic (>90 days) magnetic resonance imaging (MRI) scan. Manual thalamic segmentation was performed. Results: Younger and older children had significantly greater stroke-side thalamic volume loss compared to adults (48.2%, P = .022; 40.7%, P = .044, respectively). Conclusions: Stroke-side thalamic volumes decreased across the age spectrum but to a greater degree in pediatric patients. This observation can affect functional and cognitive outcomes post stroke and warrants further research.

Imaging Characteristics of CNS Neuroblastoma-FOXR2: A Retrospective and Multi-Institutional Description of 25 Cases

BACKGROUND AND PURPOSE

The 5th edition of the World Health Organization Classification of CNS tumors defines the CNS neuroblastoma FOXR2 in the group of embryonal tumors. Published clinical outcomes tend to suggest a favorable outcome after resection, craniospinal irradiation, and chemotherapy. This multicenter study aimed to describe imaging features of CNS neuroblastoma-FOXR2, which have been poorly characterized thus far.

MATERIALS AND METHODS

On the basis of a previously published cohort of tumors molecularly classified as CNS neuroblastoma-FOXR2, patients with available imaging data were identified. The imaging features on preoperative MR imaging and CT data were recorded by 8 experienced pediatric neuroradiologists in consensus review meetings.

RESULTS

Twenty-five patients were evaluated (13 girls; median age, 4.5 years). The tumors were often large (mean, 115 [ SD, 83] mL), showed no (24%) or limited (60%) perilesional edema, demonstrated heterogeneous enhancement, were often calcified and/or hemorrhagic (52%), were always T2WI-hyperintense to GM, and commonly had cystic and/or necrotic components (96%). The mean ADC values were low (687.8 [SD 136.3] × 10-6 mm2/s). The tumors were always supratentorial. Metastases were infrequent (20%) and, when present, were of nodular appearance and leptomeningeal.

CONCLUSIONS

In our cohort, CNS neuroblastoma FOXR2 tumors showed imaging features suggesting high-grade malignancy and, at the same time, showed characteristics of less aggressive behavior. There are important differential diagnoses, but the results of this study may assist in considering this diagnosis preoperatively.

Fetal MRI Neuroradiology: Indications

Fetal MRI is a safe, noninvasive examination of the fetus and placenta, a complement to ultrasonography. MRI provides detailed CNS evaluation, including depicting parenchymal architecture and posterior fossa morphology, and is key in prenatal assessment of spinal dysraphism, neck masses, and ventriculomegaly. Fetal MRI is typically performed after 22 weeks gestation, and ultrafast T1 and T2-weighted MRI sequences are the core of the exam, with advanced sequences such as diffusion weighted imaging used for specific questions. The fetal brain grows and develops rapidly, and familiarity with gestational age specific norms is essential to MRI interpretation.

EPEN-01. Response assessment in pediatric intracranial ependymoma: recommendations from the Response Assessment in Pediatric Neuro-Oncology (RAPNO) working group

INTRODUCTION: Ependymomas remain a major cause of cancer-related death in childhood and adolescence, with recurrence occurring in up to 50% of patients. Despite exciting molecular advances in understanding ependymoma tumorigenesis and recurrence, MRI remains the mainstay for assessing objective response to therapy and duration of disease stability. Standardized response assessment criteria for clinical trials studying pediatric intracranial ependymoma are critically needed in order to accurately compare results between studies. METHODS: To generate these standardized response criteria in pediatric intracranial ependymoma, a multidisciplinary team of pediatric neuro-oncologists, neuroradiologists, neurosurgeons, radiation oncologists, and molecular biologists formed the Response Assessment in Pediatric Neuro-Oncology (RAPNO) working group. The expert members reviewed relevant published literature, assessed current clinical practices, and engaged in iterative discussions to provide consensus recommendations for objective response assessment in pediatric intracranial ependymoma for use in prospective clinical trials. RECOMMENDATIONS AND CONCLUSIONS: The primary sequences for detecting and measuring disease and assessing radiologic response to therapy should be the contrast-enhanced T1-weighted sequence or T2-weighted sequence (T2 or T2-FLAIR) depending on which sequence the tumor is best visualized. When metastatic disease is present, only the three largest lesions will be followed in addition to any residual disease at the primary tumor focus. Importantly, the RAPNO working group notes that radiologic response to therapy is of limited value in clinical trials of patients with ependymoma, since most patients enroll on clinical trials with either no evidence of disease or only minimal disease. In recurrent or progressive disease that cannot be resected, true radiologic disease response to therapy is less clinically meaningful as a study endpoint than event-free and/or overall survival (representing prolonged stable disease) but may provide a signal of efficacy worthy of future exploration in patients with complete to near complete resections.

RARE-32. Phase 0 and feasibility single-institution clinical trial of intravenous tocilizumab for adamantinomatous craniopharyngioma

BACKGROUND: Adamantinomatous craniopharyngioma (ACP) is a devastating skull-base tumor believed to derive from epithelial remnants of the primordial craniopharyngeal duct (Rathke’s pouch), which gives rise to the anterior pituitary gland. ACP lacks medical antitumor therapies. Current standard therapy with surgery and radiation is associated with poor quality of life. Clinical and preclinical data indicate that IL-6 blockade may contribute to ACP tumor control. METHODS: Children aged 2–21 years with newly diagnosed or previously treated ACP with measurable disease are eligible for the Phase 0/feasibility single-institution clinical trial (NCT03970226) of intravenous (IV) tocilizumab at Children’s Hospital Colorado. The phase I stratum involves IV tocilizumab prior to a standard-of-care surgical resection. The feasibility portion of the trial involves IV tocilizumab every two weeks for up to 13 28-day cycles. Tocilizumab is administered at the established weight-based pediatric dosage of 8 mg/kg for patients who weigh ≥30kg or 12 mg/kg for patients who weigh <30kg. RESULTS: To date, three patients have been enrolled on the Phase 0 component of the trial. These patients demonstrated clinically relevant levels of tocilizumab (≥ 4µg/mL) in serum, cyst fluid, and/or tumor tissue, compared to undetectable levels in control samples. Two patients (1 male and 1 female; median age 10.5 years) have enrolled on the feasibility stratum; one patient had best response of minor response but met definition of progressive disease at cycle 11. One patient with extensive disease required dose reduction for myelosuppression. CONCLUSION: Systemic delivery of tocilizumab at the established pediatric dosage is promising for treatment of ACP based on preclinical work and its demonstrated penetration into cystic and solid portions of ACP tumors. The therapy to date has been well tolerated overall. Further study is planned through a CONNECT consortium international Phase II trial.

IMG-05 Imaging characteristics of CNS NB-FOXR2 – a retrospective and MULTI-INSTITUTIONAL DESCRIPTION OF 25 CASES

BACKGROUND: The CNS neuroblastoma with forkhead box R2 (CNS NB-FOXR2) activation is one of the new embryonal tumor entities in the WHO CNS tumor classification 2021. The data currently available suggest a comparably favourable outcome after craniospinal irradiation and chemotherapy. The entity is poorly characterized on imaging. We therefore aimed to describe imaging features in a multi-center patient cohort. MATERIAL AND METHODS: Molecularly and histologically confirmed CNS NB-FOXR2 tumors were retrospectively collected at six pediatric oncology centers. The imaging features on preoperative MRI and CT data were recorded by 8 experienced pediatric (neuro)radiologists in consensus. RESULTS: Twenty-five patients were identified (13 females). The majority of tumors were large at presentation (mean 115 ± SD 83 ml), showed mostly none or little perifocal edema, enhanced only partly, were often calcified and/or hemorrhagic, were always T2w hyperintense to gray matter, and often had cystic and/or necrotic components. The min. mean ADC values were relatively low (mean 687.8 ± SD 136.3 in 10-6mm2/s). The tumors originated never infratentorial and were never centered in the midline. Metastases were rare. CONCLUSIONS: For the first time, imaging characteristics of the recently described CNS NB-FOXR2 are described in a multi-center cohort. The results of this study may assist in diagnosing these tumors preoperatively. Collaborative pooling of cases is important to gain insight into typical imaging features of rare tumors, especially in view of the increasing molecular-driven subtyping.

Age-related changes in the completeness of the circle of Willis in children

PURPOSE

The circle of Willis is a circulatory anastomosis that supplies blood to the brain. If any of the bridging segments are hypoplastic or absent, the capacity for collateral flow in the setting of large vessel occlusion may be decreased. Outside of the neonatal period, the prevalence of a complete circle of Willis (CoW) in the pediatric population has not been well described. Our objectives include determining the prevalence of a complete CoW in children and identifying if there is an age-related "loss" of arterial segments.

METHODS

Following IRB approval, angiograms of the CoW performed on a 3-T MR platform from 2016 to 2020 on patients 21 years or younger were retrospectively reviewed. Any patient with underlying arterial pathology that may affect the CoW was excluded. Patient age and gender at the time of imaging were obtained.

RESULTS

In total, 592 pediatric CoW were assessed. Frequencies of completeness were calculated in two different fashions: scenario 1 where a CoW was characterized as complete even if it contained hypoplastic vessels (88.8%), and scenario 2 where it was characterized as complete after excluding hypoplastic vessels (44.0%). In both scenarios, our data showed that older age was more associated with an incomplete CoW (p < 0.0001). In addition, we found a higher percentage of males with an incomplete CoW compared with females (p < 0.0001).

CONCLUSIONS

The presence of a complete CoW is greater in our pediatric population than what has been reported in adults. The prevalence of an incomplete circle of Willis also increases significantly with age.

Whole-exome sequencing and adrenocorticotropic hormone therapy in individuals with infantile spasms

AIM

To identify additional genes associated with infantile spasms using a cohort with defined infantile spasms.

METHOD

Whole-exome sequencing (WES) was performed on 21 consented individuals with infantile spasms and their unaffected parents (a trio-based study). Clinical history and imaging were reviewed. Potentially deleterious exonic variants were identified and segregated. To refine potential candidates, variants were further prioritized on the basis of evidence for relevance to disease phenotype or known associations with infantile spasms, epilepsy, or neurological disease.

RESULTS

Likely pathogenic de novo variants were identified in NR2F1, GNB1, NEUROD2, GABRA2, and NDUFAF5. Suggestive dominant and recessive candidate variants were identified in PEMT, DYNC1I1, ASXL1, RALGAPB, and STRADA; further confirmation is required to support their relevance to disease etiology.

INTERPRETATION

This study supports the utility of WES in uncovering the genetic etiology in undiagnosed individuals with infantile spasms with an overall yield of five out of 21. High-priority candidates were identified in an additional five individuals. WES provides additional support for previously described disease-associated genes and expands their already broad mutational and phenotypic spectrum.

RARE-11. QUANTITATIVE MR IMAGING FEATURES ASSOCIATED WITH UNIQUE TRANSCRIPTIONAL CHARACTERISTICS IN PEDIATRIC ADAMANTINOMATOUS CRANIOPHARYNGIOMA: A POTENTIAL GUIDE FOR THERAPY

METHODS

Through the Advancing Treatment for Pediatric Craniopharyngioma (ATPC) consortium we accumulated preoperative MRIs and tumor RNA for 50 unique ACP patients. MRIs were assessed quantitatively for 28 different features and analyzed using Multiple Factor Analysis (MFA) and optimal clustering was determined via maximization of Bayesian Information Criterion (BIC). Following bulk RNAseq, differential expression and pathway enrichment were performed using standard methodologies (i.e., DESeq2 and GSEA).

RESULTS

MRI features were well represented in the first 3 dimensions of MFA (variance explained=67.32%); specifically tumor/cyst size, ventricular size, and cyst fluid diffusivity. Using this three-way axis, we identified 3 patient subgroups. Transcriptional differences between these subgroups indicated one group was enriched for DNA damage response and MYC related pathways, one group enriched for SHH, and one group enriched for WNT/β-catenin and EMT-related pathways.

CONCLUSION

This preliminary work suggests that there may be unique gene expression variants within ACP, which may be identified preoperatively using easily quantifiable MRI parameters. These radiogenomic signatures could provide prognostic information and/or guidance in the selection of antitumor therapies for children with ACP.

Relapsing Demyelinating Syndromes in Children: A Practical Review of Neuroradiological Mimics

Relapsing demyelinating syndromes (RDS) in children encompass a diverse spectrum of entities including multiple sclerosis (MS) acute disseminated encephalomyelitis (ADEM), aquaporin-4 antibody associated neuromyelitis optica spectrum disorder (AQP4-NMOSD) and myelin oligodendrocyte glycoprotein antibody disease (MOG-AD). In addition to these, there are “antibody-negative” demyelinating syndromes which are yet to be fully characterized and defined. The paucity of specific biomarkers and overlap in clinical presentations makes the distinction between these disease entities difficult at initial presentation and, as such, there is a heavy reliance on magnetic resonance imaging (MRI) findings to satisfy the criteria for treatment initiation and optimization. Misdiagnosis is not uncommon and is usually related to the inaccurate application of criteria or failure to identify potential clinical and radiological mimics. It is also notable that there are instances where AQP4 and MOG antibody testing may be falsely negative during initial clinical episodes, further complicating the issue. This article illustrates the typical clinico-radiological phenotypes associated with the known pediatric RDS at presentation and describes the neuroimaging mimics of these using a pattern-based approach in the brain, optic nerves, and spinal cord. Practical guidance on key distinguishing features in the form of clinical and radiological red flags are incorporated. A subsection on clinical mimics with characteristic imaging patterns that assist in establishing alternative diagnoses is also included.

Cost and Utility of Routine Contrast-Enhanced Neck MRA in a Pediatric MRI Stroke Evaluation Protocol

BACKGROUND AND PURPOSE

Cervical arterial dissection is one of the frequent causes of pediatric arterial ischemic stroke. Out of concern for missing cervical arterial dissection in patients in whom pediatric stroke is suspected, our tertiary children's hospital added contrast-enhanced 3D neck MR angiography to every pediatric stoke work-up. This research investigated whether the routine use of contrast-enhanced neck MRA in our MR imaging stroke protocol ever detected a cervical arterial abnormality when the DWI, SWI/gradient recalled-echo, or circle of Willis MRA findings from the brain MR imaging were reported as normal.

MATERIALS AND METHODS

The institutional PACS data base was searched for stroke protocol MRIs that included DWI, gradient recalled-echo or SWI, circle of Willis MRA, and 3D contrast-enhanced neck MRA in patients younger than 18 years of age with examinations performed between September 2010 and June 2017.

RESULTS

In only a single case (0.15%) were the DWI, SWI/gradient recalled-echo, or circle of Willis MRA findings all separately reported as normal and the contrast-enhanced neck MRA findings reported as abnormal. To reach these findings, we screened 681 patients, which would have resulted in an estimated >$200,000 in Medicare charges and $80,000 in of out-of-pocket cost to patients.

CONCLUSIONS

In our large series, the addition of a routine contrast-enhanced neck MRA to our pediatric stroke MR imaging protocol was of extremely low yield. We believe the use of neck MRA should reasonably be limited to cases in which abnormalities are initially detected on standard brain sequences or to patients with atypical presentation or recurrent pathology.

Diagnostic accuracy of neuroimaging in pediatric optic chiasm/sellar/suprasellar tumors

Preoperative diagnosis for tumors arising in the optic chiasm/sellar/suprasellar region in children is helpful to determine surgical necessity and approach, given the high operative risk in this area. We evaluated the ability to differentiate tumor type by preoperative neuroimaging. Thirty-eight of 53 tumors were correctly diagnosed by neuroimaging based on final pathologic diagnosis (prediction accuracy 72%). Prediction accuracies were 87% (20/23) for craniopharyngioma, 79% (11/14) for optic pathway glioma, 64% (7/11) for germ cell tumor, and 0% (0/5) for Langerhans cell histiocytosis. Diagnosis of optic chiasm/sellar/suprasellar tumors in children by imaging alone should be considered when biopsy is considered high risk.

Abstract WMP116: Acute Infarct Volume in Childhood Stroke Can Be Accurately Estimated by Modelling Contraction of Chronic Infarction

Introduction: Arterial ischemic stroke (AIS) occurs in 1-2 children/100,000/year. Most children have neurologic deficits post-AIS, but the influence of infarct volume on neurologic outcome is understudied. While acute infarct volume {best measured as a percentage of total brain volume infarcted (%aTBVi) in the growing brain} likely predicts outcome, acute scans are not always available in children. Chronic infarct volumes are underestimated by direct measurement due to contraction. A method for estimating acute infarct volumes from chronic scans is needed. We developed and compared the reliability of three methods for estimating the %aTBVi from values measured on chronic images.

Methods: A retrospective IRB-approved study studying children (age 1 month-17 years) with AIS enrolled 158 patients. Those with acute (<3 days) and chronic (>90 days) MRIs were manually segmented by a pediatric neuroradiologist. Method 1 (direct method, used as control) estimated %aTBVi by measuring chronic infarct volume (cVI) and dividing by total brain volume. Method 2 (OFC method) estimated %aTBVi by subtracting the total non-infarcted brain volume from an extrapolated total brain volume based on orbitofrontal circumference (OFC). Method 3 (contraction method, Figure 1) used a regression model to apply a correction factor to the direct measurement of cVI that was then divided by total brain volume to estimate %aTBVi. Intraclass correlation compared estimated %aTBVi of the three methods to the gold standard %aTBVi calculated from manual segmentation of acute scans.

Results: Inclusion criteria were met by 86 patients. The control direct method had excellent reliability (ICC 0.79), although it was exceeded by the contraction method (Figure 1, ICC=0.86), while the OFC method reliability was poor (ICC=0.42).

Conclusion: %aTBVi is reliably estimated in children with AIS with only chronic imaging via the contraction method.

Sacral agenesis and fecal incontinence: how to increase the index of suspicion

PURPOSE

Sacral abnormalities range from missing the coccyx, a few sacral vertebrae, or hemi-sacrum, to complete absence with fused iliac bones. The purpose of this study was to review the association between sacral agenesis and fecal incontinence to help inform patient prognosis.

METHODS

A retrospective review was performed of patients who presented for bowel management due to sacral agenesis at a tertiary care children's hospital between 2016 and 2017 (n = 10). Data collection included: gender, time of diagnosis, sacral ratio, and associated anomalies. Patients with anorectal malformation and sacrococcygeal teratomas were excluded.

RESULTS

Four patients were female. Seven patients had a delayed diagnosis ranging from 22 months of age to 9 years. Most common symptoms included failure of age-appropriate toilet training and severe diaper rash. The sacral ratio was zero (6), 0.3 and 0.4 (2), and hemi-sacrum (2). Associated anomalies were present in five patients.

CONCLUSION

Sacral abnormalities should be suspected in patients who present with early severe diaper rash and those who fail to toilet train. An abdominal radiograph can evaluate the sacrum, when the sacral ratio is 0.4 or less, parents should be counseled regarding fecal incontinence and neurogenic bladder.

The conus medullaris ratio: A new way to identify tethered cord on MRI

PURPOSE

Approximately 25% of patients with anorectal malformation have tethered cord. The traditional way of determining conus medullaris level on magnetic resonance imaging (MRI) relies on counting vertebrae, which may be challenging due to vertebral numeric variation, segmentation anomalies, as well as transitional vertebral body anatomy. The purpose of this study was to utilize more reliable anatomic landmarks (foramen magnum, conus termination, and the upper limit of the iliac crest) to establish a consistent ratio that may differentiate patients with normal and low-lying conus.

METHODS

A single institution database search identified two groups of patients: 255 with normal and 85 with abnormal spinal MRI, who underwent tethered cord release. The conus medullaris ratio was calculated in both groups. The ratio was obtained by dividing the distance between the conus level and the iliac crest by the distance between the foramen magnum and the conus level (IRB # 16-2330).

RESULTS

The mean ratio was significantly higher in the non-tethered group compared to the tethered patients (0.184 [sd 0.03] versus 0.118 [sd 0.09]; P < .0001). The ratio proved to be a good discriminator between normal and abnormal patients, with area under the curve (AUC) equal to 0.749, meaning that at random, there is a 75% chance that the tethered cord patient will have a lower ratio than the non-tethered cord patient.

CONCLUSION

"The Conus Medullaris Ratio" is a good predictor of low-lying conus level on MRI and offers an easy alternative to counting vertebral body levels, particularly in patients with variant or abnormal vertebral body anatomy.

LEVEL OF EVIDENCE

II, Study of Diagnostic Test.

Occult head injury is common in children with concern for physical abuse

BACKGROUND

Studies evaluating small patient cohorts have found a high, but variable, rate of occult head injury in children <2 years old with concern for physical abuse. The American College of Radiology (ACR) recommends clinicians have a low threshold to obtain neuroimaging in these patients.

OBJECTIVES

Our aim was to determine the prevalence of occult head injury in a large patient cohort with suspected physical abuse using similar selection criteria from previous studies. Additionally, we evaluated proposed risk factors for associations with occult head injury.

MATERIALS AND METHODS

This was a retrospective, secondary analysis of data collected by an observational study of 20 U.S. child abuse teams that evaluated children who underwent subspecialty evaluation for concern of abuse. We evaluated children <2 years old and excluded those with abnormal mental status, bulging fontanelle, seizure, respiratory arrest, underlying neurological condition, focal neurological deficit or scalp injury.

RESULTS

One thousand one hundred forty-three subjects met inclusion criteria and 62.5% (714) underwent neuroimaging with either head computed tomography or magnetic resonance imaging. We found an occult head injury prevalence of 19.7% (141). Subjects with emesis (odds ratio [OR] 3.5, 95% confidence interval [CI] 1.8-6.8), macrocephaly (OR 8.5, 95% CI 3.7-20.2), and loss of consciousness (OR 5.1, 95% CI 1.2-22.9) had higher odds of occult head injury.

CONCLUSION

Our results show a high prevalence of occult head injury in patients <2 years old with suspected physical abuse. Our data support the ACR recommendation that clinicians should have a low threshold to perform neuroimaging in patients <2 years of age.

Anesthetic Considerations for a Child With Rare B3GALT6 Mutations: A Case Report

A rare autosomal recessive disorder caused by mutations in the B3GALT6 gene on chromosome 1p36 results in deficiency of β-1,3-galactosyltransferase 6, an enzyme critical for glycosaminoglycan biosynthesis. Defects in this gene result in a phenotype that has features of both skeletal dysplasia and a connective tissue disorder. The anesthetic considerations for children with this disorder have not previously been described. We report a collaborative, multidisciplinary approach to the perioperative care of a child with B3GALT6 mutations with severe phenotypic expression.

Significance of FDG-PET Hypermetabolism in Children with Intractable Focal Epilepsy

BACKGROUND

Interictal 18F-fluorodeoxyglucose-positron emission topography (FDG-PET) hypometabolism is routinely used in the presurgical workup of children with medically intractable epilepsy (MIE). FDG-PET hypermetabolism, however, is rarely seen, and the significance of this finding in the epilepsy workup is not well established.

METHODS

We performed a retrospective study of patients who underwent FDG-PET during the presurgical workup of MIE over a 4-year period, between 1 January 2010 and 31 December 2013, at the Children's Hospital Colorado, CO, USA.

RESULTS

Focal FDG-PET hypermetabolism was identified in 7 (2.2%) of 317 patients. The median age was 124 months, all cases with catastrophic epilepsy. Surface electroencephalography (EEG) performed concomitantly with FDG injections revealed ictal EEG discharges in 2 patients, frequent interictal epileptiform discharges (IEDs) in 3, occasional IEDs in 1, and no IEDs in 1. All 7 patients underwent functional hemispherectomies. Histopathology revealed type 1 focal cortical dysplasia in all patients. Six (86%) were completely seizure-free (Engel class I) and 1 had extremely infrequent seizures (Engel class II) (mean follow-up, 47.4 months).

CONCLUSION

While a rare finding, interictal PET hypermetabolism does occur, may help identify epileptogenic zones, and assessment to reveal it should be made by concomitant use of surface EEG during PET scans.

Common data elements for clinical research in mitochondrial disease: a National Institute for Neurological Disorders and Stroke project

OBJECTIVES

The common data elements (CDE) project was developed by the National Institute of Neurological Disorders and Stroke (NINDS) to provide clinical researchers with tools to improve data quality and allow for harmonization of data collected in different research studies. CDEs have been created for several neurological diseases; the aim of this project was to develop CDEs specifically curated for mitochondrial disease (Mito) to enhance clinical research.

METHODS

Nine working groups (WGs), composed of international mitochondrial disease experts, provided recommendations for Mito clinical research. They initially reviewed existing NINDS CDEs and instruments, and developed new data elements or instruments when needed. Recommendations were organized, internally reviewed by the Mito WGs, and posted online for external public comment for a period of eight weeks. The final version was again reviewed by all WGs and the NINDS CDE team prior to posting for public use.

RESULTS

The NINDS Mito CDEs and supporting documents are publicly available on the NINDS CDE website ( https://commondataelements.ninds.nih.gov/ ), organized into domain categories such as Participant/Subject Characteristics, Assessments, and Examinations.

CONCLUSION

We developed a comprehensive set of CDE recommendations, data definitions, case report forms (CRFs), and guidelines for use in Mito clinical research. The widespread use of CDEs is intended to enhance Mito clinical research endeavors, including natural history studies, clinical trial design, and data sharing. Ongoing international collaboration will facilitate regular review, updates and online publication of Mito CDEs, and support improved consistency of data collection and reporting.

Clinical metagenomic identification of Balamuthia mandrillaris encephalitis and assembly of the draft genome: the continuing case for reference genome sequencing

Background

Primary amoebic meningoencephalitis (PAM) is a rare, often lethal, cause of encephalitis, for which early diagnosis and prompt initiation of combination antimicrobials may improve clinical outcomes.

Methods

In this study, we sequenced a full draft assembly of the Balamuthia mandrillaris genome (44.2 Mb in size) from a rare survivor of PAM, and recovered the mitochondrial genome from six additional Balamuthia strains. We also used unbiased metagenomic next-generation sequencing (NGS) and SURPI bioinformatics analysis to diagnose an ultimately fatal case of Balamuthia mandrillaris encephalitis in a 15-year-old girl.

Results and Discussion

Comparative analysis of the mitochondrial genome and high-copy number genes from six additional Balamuthia mandrillaris strains demonstrated remarkable sequence variation, and the closest Balamuthia homologs corresponded to other amoebae, hydroids, algae, slime molds, and peat moss. Real-time NGS testing of hospital day 6 CSF and brain biopsy samples detected Balamuthia on the basis of high-quality hits to 16S and 18S ribosomal RNA sequences present in the National Center for Biotechnology Information (NCBI) nt reference database. The presumptive diagnosis of PAM by visualization of amoebae on brain biopsy histopathology and NGS analysis was subsequently confirmed at the US Centers for Disease Control and Prevention (CDC) using a Balamuthia-specific PCR assay. Retrospective analysis of a day 1 CSF sample revealed that more timely identification of Balamuthia by metagenomic NGS, potentially resulting in a better clinical outcome, would have required availability of the complete genome sequence.

Conclusions

These results underscore the diverse evolutionary origins of Balamuthia mandrillaris, provide new targets for diagnostic assay development, and will facilitate further investigations of the biology and pathogenesis of this eukaryotic pathogen. The failure to identify PAM from a day 1 sample without a fully sequenced Balamuthia genome in the database highlights the critical importance of whole-genome reference sequences for microbial detection by metagenomic NGS.

Electronic supplementary material

The online version of this article (doi:10.1186/s13073-015-0235-2) contains supplementary material, which is available to authorized users.

Excision of the primary tumour in patients with metastatic breast cancer: a clinical dilemma

BACKGROUND

Approximately 10% of new breast cancer patients will present with overt synchronous metastatic disease. The optimal local management of those patients is controversial. Several series suggest that removal of the primary tumour is associated with a survival benefit, but the retrospective nature of those studies raises considerable methodologic challenges. We evaluated our clinical experience with the management of such patients and, more specifically, the impact of surgery in patients with synchronous metastasis.

METHODS

We reviewed patients with primary breast cancer and concurrent distant metastases seen at our centre between 2005 and 2007. Demographic and treatment data were collected. Study endpoints included overall survival and symptomatic local progression rates.

RESULTS

The 111 patients identified had a median follow-up of 40 months (range: 0.6-71 months). We allocated the patients to one ot two groups: a nonsurgical group (those who did not have breast surgery, n = 63) and a surgical group (those who did have surgery, n = 48, 29 of whom had surgery before the metastatic diagnosis). When compared with patients in the nonsurgical group, patients in the surgical group were less likely to present with T4 tumours (23% vs. 35%), N3 nodal disease (8% vs. 19%), and visceral metastasis (67% vs. 73%). Patients in the surgical group experienced longer overall survival (49 months vs. 33 months, p = 0.01) and lower rates of symptomatic local progression (14% vs. 44%, p < 0.001).

CONCLUSIONS

In our study, improved overall survival and symptomatic local control were demonstrated in the surgically treated patients; however, this group had less aggressive disease at presentation. The optimal local management of patients with metastatic breast cancer remains unknown. An ongoing phase iii trial, E2108, has been designed to assess the effect of breast surgery in metastatic patients responding to first-line systemic therapy. If excision of the primary tumour is associated with a survival benefit, then the preselected subgroup of patients who have responded to initial systemic therapy is the desired population in which to put this hypothesis to the test.

P2-15-05: Excision of the Primary Tumour in Patients with Metastatic Breast Cancer – Will E2108 Provide the Definitive Answer?

Background: Approximately 10% of new breast cancer patients will present with overt synchronous metastatic disease. Controversy exists about the optimal local management of these patients. While several series suggest that removal of primary tumour is associated with a survival benefit, the retrospective nature of these studies raises considerable methodological challenges. We decided to evaluate the experience at our centre around the impact of surgery in patients with synchronous metastasis.

Method: Case records of all patients seen with primary breast cancer and concurrent distant metastases between 2005 to 2007 were reviewed. Demographic and treatment data was collected. The study endpoints compared both overall survival and symptomatic local progression rates between patients who had breast surgery and those who did not.

RESULTS: 111 patients were identified. Median follow-up 40 months (0.6-71 months). Patients were divided into two groups: those patients who underwent breast surgery (n=48; 29/48 had surgery immediate prior to metastatic diagnosis) and those that did not have surgery(n = 63). The surgical group were less likely to present with T4 tumours (20% vs 36%), N3 nodal disease (8% vs 19%) and visceral metastasis (67% vs 73%)when compared with non-surgical group. Improved overall survival (49 months vs 33 months; p=0.01) and less symptomatic local progression rates ( 15% vs 43%, p &lt; 0.001 ) were seen in the surgical group compared to the non-surgical group.

CONCLUSIONS: The optimal local management of patients with metastatic breast cancer is unknown. Despite the surgery group demonstrating an improved overall survival and symptomatic local control, this group had less aggressive disease at presentation. These results confirm the need for prospective randomized studies. E2108, an ongoing Phase III Trial, was designed to assess the effect of breast surgery in metastatic patients responding to first line systemic therapy. If excision of the primary tumour is associated with a survival benefit, then the pre-selected subgroup of patients that have responded to initial systemic therapy is the desired population to put this hypothesis to test.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-15-05.

P4-15-01: High Prevalence of Prospective Memory (PM) Impairment in Early Breast Cancer (EBC) Survivors within 1 Year of Adjuvant Chemotherapy Completion: Novel Findings Concerning Post Chemotherapy Cognitive Effects

Background Numerous studies have demonstrated that EBC survivors report more memory problems than healthy controls. However, evidence of impairment on objective tests of memory remains inconclusive. Past research has focussed exclusively on retrospective memory (remembering information from the past when asked to do so), but the complaints of EBC patients appear better described as “prospective memory” failures defined as forgetting to carry out in the future previously formed intentions. The effective performance of many day-to-day activities relies on PM and its impairment has negative consequences in everyday life. Despite its high ecological relevance, no study has evaluated PM functioning in EBC survivors. Consequently, we assessed the prevalence of PM impairment among EBC survivors in the year following completion of chemotherapy. Methods We undertook a cross sectional quantitative case-control study aiming to recruit 80 patients from the Ottawa Hospital Regional Cancer Centre and 80 matched healthy controls from the community. Patients were within 1 year of having completed a first course of chemotherapy. A standardized test of prospective memory (Memory for Intention Screening Test) was administered to both groups. Following the International Cognition and Cancer Task Force recommendation (2008), impairment was defined as a score that fell one standard deviation below the mean performance of the control group. Standardized measures of depression (CESD), anxiety (STAI) and fatigue (Fact-F) were also completed. Results Data are available on 36 patients and 18 controls. Age was well balanced between the groups (case-control mean age 54y vs. 51y, respectively, p=.204). Overall PM impairment was observed in 41% of the participants. More importantly, the rate of PM impairment was significantly higher in the EBC group than controls (53% vs 17%; p &lt; 0.005; odds ratio = 5.588; 95% CI=1.376 to 22.7). Multivariate logistic regression showed that PM performance was unaffected by age (p=0.459), depression (p=0.358), anxiety (p=0.512) or fatigue (p=0.595). Conclusions These preliminary findings provide further support for the hypothesis that breast cancer treatment can impair cognitive processes and yield new and important insights into the type of memory problems experienced by EBC survivors. They suggest that a significant proportion of patients exhibit deficits in PM, an aspect of memory involved in effective daily functioning. Our results also suggest that emotional distress and fatigue do not contribute to PM functioning. Further studies in this area should be directed at understanding the severity and duration of PM impairment. Acknowledging and studying this vexing problem in EBC survivors will aid in developing appropriate rehabilitation strategies.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-15-01.

A randomized controlled trial (RCT) of long-term follow-up for early stage breast cancer comparing family physician to specialist care: A report of secondary outcomes

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Background: Breast cancer patients usually receive follow-up in specialist cancer clinics. We have reported that family physician follow-up of breast cancer patients is a safe and acceptable alternative to specialist follow-up as measured by the primary clinical outcome of the rate of serious clinical events (Grunfeld et al, JCO 2006;24(6)). We report here the secondary outcomes of this trial: quality of life domains, patient satisfaction and patients’ costs. Methods: Women with early stage breast cancer who had completed adjuvant therapy (patients may have continued on adjuvant hormonal therapy), who were disease free and between 9 and 15 months after diagnosis, were allocated to receive follow-up in a cancer clinic according to usual practice (CC arm) or follow-up from their own family physician (FP arm). For patients without recurrence, quality of life (QL) measured by the SF36, patient satisfaction, and patients’ costs were measured every 6 months. For patients with recurrence QL measured by the EORTC QLQ C-30 was measured at the time of recurrence. Results: 483 patients were allocated to the FP arm and 485 to the CC arm. Median follow-up was 3.5 years. There were no significant differences between groups on change scores for SF36 subscales to 24 months, or EORTC functional subscale scores at the time of recurrence. Patients’ costs of follow-up (travel costs, out-of-pocket expenses, and lost earnings) were significantly less to 24 months (p < 0.02) in the FP arm. Although costs were less between 36 and 48 months, these were not significant. Conclusions: Family physician follow-up of breast cancer patients does not have a negative impact on clinical or QL outcomes and is less costly for patients.

No significant financial relationships to disclose.

Resection margin status in lumpectomy specimens for duct carcinoma of the breast: correlation with core biopsy and mammographic findings

BACKGROUND

The strategy for surgical treatment of breast carcinoma proven by biopsy is mainly based on the physical and mammographic examinations. To investigate if the pathological findings in core biopsy are contributory to planning the surgical strategy, we correlated the status of ductal carcinoma in situ (DCIS) in the core needle biopsy of breast, the mammographic changes and the status of resection margins in the subsequent lumpectomy.

STUDY DESIGN

Consecutive 130 core needle biopsies with prior mammography and subsequent lumpectomy were reviewed. Biopsies were divided into: group I, DCIS; group II, DCIS and infiltrating carcinoma (IC); and group III, IC. Mammographic findings were categorized into four groups: (a) nonspecific findings; (b) calcification (Ca(++)); Ca(++) and mass, and mass only. The status of margins in correlating lumpectomy specimens was reviewed. Close margin was defined as a free margin at less than 0.1cm from the carcinoma.

RESULTS

The rates of positive or close margins in three groups I, II, and III were 13/18, 18/48, and 2/64 (P < 0.001); and in mammography groups of nonspecific finding, Ca(++), Ca(++) mass and mass only were 5/6, 7/15, 8/37, and 13/72 (P < 0.001), respectively. Of the total of 14 cases with positive margins of more than 0.5 cm in length, 8, 4, and 2 cases were from group I, II, and II, respectively. In addition, 13 of 21 cases with nonspecific changes or with only Ca(++) in mammograms belonged to the group I; 10 of these 13 cases were associated with positive margins. Forty-one of 72 cases presenting as a mass only in mammograms belonged to the group III; only 2 of these 41 cases were associated positive margins.

CONCLUSIONS

Correlation of the extent of carcinoma with pre-operative histopathological findings was better than with mammography. Core biopsies containing only DCIS, particularly in cases with nonspecific findings or with only Ca(++) in mammograms, represent a group of breast carcinoma that pose the high risk for incomplete resection in lumpectomy. Surgical management of patients having these cores includes wider resection margins than would otherwise be taken. Most core biopsies with only IC were associated with negative margins.

Waiting times from abnormal breast screen to diagnosis in 7 Canadian provinces

BACKGROUND

Delay to breast cancer diagnosis following an abnormal screening result is associated with anxiety and personal disruption. We assessed the patterns and timeliness of diagnostic follow-up after breast cancer screening for women with abnormal results who attended organized screening programs in 7 provinces.

METHODS

Using data from the Canadian Breast Cancer Screening Database, we identified 203,141 women aged 50-69 years who underwent screening in 1996 through provincially organized breast cancer screening programs in British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Nova Scotia and Newfoundland. We prospectively followed women with an abnormal screening result through to the completion of the assessment process. We evaluated the waiting times from screening examination to first assessment, from screening examination to first imaging, from screening examination to diagnosis and from first assessment to diagnosis for 13,958 women, stratified according to screening program, mode of detection, whether a biopsy was performed and whether cancer was diagnosed.

RESULTS

We observed considerable variations between and within programs in the time to diagnosis. The median time from screening examination to first assessment was 2.6 weeks. The median time from screening examination to diagnosis was 3.7 weeks; this time increased to 6.9 weeks for women undergoing biopsy. Even when no biopsy was performed, 10% of the women waited 9.6 weeks or longer for a diagnosis, as compared with 15.0 weeks or longer for 10% of the women undergoing biopsy. Among the women who had a biopsy, the use of core biopsy was associated with a shorter median time to diagnosis than was open biopsy, and those found to have cancer had shorter waiting times than women with benign biopsy findings.

INTERPRETATION

Women undergoing assessment of an abnormal breast cancer screening result waited many weeks for a diagnosis, especially when a biopsy was performed. To ensure that targets for timeliness, adopted nationally in 1999, are realized, improved models of care or dissemination of existing efficient techniques to reach a diagnosis will be needed.